Jegorovs, J.J.JegorovsMohring, J.J.Mohring2022-03-032022-03-032005https://publica.fraunhofer.de/handle/publica/2100162-s2.0-27844437632In this work we derive a third order correction to the classical Helmholtz equation. Starting from non-linear Euler equations and using asymptotical analysis we get a decoupled system of linear, Helmholtz type equations, which are written in terms of the acoustical pressure functions. We present also a rather simple concept of the boundary conditions. Also numerical results and accompanying difficulties are discussed and presented.en003510journal article